Traffic signal control method, device, equipment and storage medium

Abstract

Embodiments of the present application disclose a traffic signal control method, device and equipment, and a storage medium. The method comprises: performing isolated optimization processing on the basis of historical traffic data of N isolated intersections by an isolated intersection optimization model to obtain N traffic signal information corresponding to the N isolated intersections, wherein the traffic signal information comprises a display duration of a traffic signal light allowing traffic and a signal cycle; one isolated intersection corresponds to one traffic signal information; and performing traffic signal control optimization processing in the direction of maximum road network green wave bandwidth on the basis of the N traffic signal information by a road network green wave coordination optimization model to obtain a traffic signal coordination control scheme of the road network. The embodiments of the present application can accurately determine the cycle and duration of the traffic signal light, and effectively relieve traffic congestion.

Description

Technical Field

[0001] This application relates to the field of traffic signal control technology, and in particular to traffic signal control methods, devices, equipment and storage media. Background Technology

[0002] In recent years, with the acceleration of urbanization, the number of cars has grown rapidly. Intersections are bottlenecks in urban traffic networks, so optimizing signal control at urban intersections can alleviate urban traffic problems.

[0003] Traffic light control at urban intersections is a traffic control method that integrates road space-time resources. Since the first traffic light appeared at a street intersection in London, England in 1868, over a century of development in electronic technology, modern information technology, automatic control technology, and computer technology has led to the rapid adoption of traffic light-based traffic control methods. How to control traffic flow based on traffic lights, especially at intersections, has become one of the key research issues in the field of traffic signal control. Summary of the Invention

[0004] This application provides a traffic signal control method, apparatus, device, and storage medium, which can optimize intersection signal control based on long-term historical traffic data to alleviate urban traffic congestion.

[0005] On one hand, embodiments of this application provide a traffic signal control method, including:

[0006] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the permitted communication traffic signal, etc.; one isolated intersection corresponds to one traffic signal information.

[0007] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0008] On one hand, embodiments of this application provide a traffic signal control device, including:

[0009] The optimization unit is used to perform isolated optimization processing based on historical traffic data of N isolated intersections using an isolated intersection optimization model, to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of permitted communication traffic signals, etc.; one isolated intersection corresponds to one traffic signal information.

[0010] The processing unit is used to optimize traffic signal control based on the N traffic signal information by using the road network green wave coordination optimization model in the direction with the largest road network green wave bandwidth, so as to obtain the traffic signal coordination control scheme of the road network.

[0011] On one hand, embodiments of this application provide a traffic signal control device, including:

[0012] A processor, suitable for implementing one or more computer programs; a computer storage medium storing one or more computer programs adapted to be loaded and executed by the processor:

[0013] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the permitted communication traffic signal, etc.; one isolated intersection corresponds to one traffic signal information.

[0014] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0015] On one hand, embodiments of this application provide a computer storage medium storing a computer program, which, when executed by a processor of a traffic signal control device, is used to perform:

[0016] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the permitted communication traffic signal, etc.; one isolated intersection corresponds to one traffic signal information.

[0017] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0018] On one hand, embodiments of this application provide a computer program product or a computer program, the computer program product including a computer program, which may refer to a computer program, and the computer program is stored in a computer storage medium; a processor reads the computer program from the computer storage medium, and the processor executes the computer program, causing the traffic signal control equipment to perform:

[0019] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the permitted communication traffic signal, etc.; one isolated intersection corresponds to one traffic signal information.

[0020] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0021] In this embodiment, firstly, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections, resulting in N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the permitted traffic light, with one traffic signal information corresponding to one isolated intersection. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to optimize traffic signal control according to the direction with the maximum green wave bandwidth, resulting in a traffic signal coordination control scheme for the road network. Since traffic demand / flow follows certain patterns in the long term, optimizing the traffic signal information of each isolated intersection based on long-term historical traffic data and the isolated intersection optimization model is relatively accurate. Using the traffic signal information of each isolated intersection as input, the road network green wave coordination optimization model is used to coordinate and optimize the road network traffic lights, determining a suitable traffic signal coordination control scheme for the current road network. Controlling the permitted traffic lights of the N isolated intersections according to the determined traffic signal coordination control scheme ensures that the road network has the maximum green wave bandwidth, thereby effectively alleviating traffic congestion. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic flowchart of a traffic signal control method provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of a four-entry intersection provided in an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of a road network provided in an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of green wave bandwidth calculation provided in an embodiment of this application.

[0027] Figure 5 This is a schematic diagram of another traffic signal control method provided in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the structure of a traffic signal control device provided in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram of the structure of a traffic signal control device provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be noted that all information related to the object in social applications, such as avatars, virtual images, and names, in the following description of this application has been obtained with the permission of the respective object.

[0031] Traffic lights have evolved from manual to automatic control, traffic signal cycles from fixed to variable cycles, and system control methods from timed control and sensor control to adaptive control. In terms of development history and spatial relationships, the focus has expanded from controlling individual, isolated intersections to considering the relationships between adjacent intersections, coordinating signals at various intersections on arterial roads, and ultimately to the comprehensive allocation and control of all intersections within the city's regional road network.

[0032] With the rapid development of information technology, traffic flow information (also known as historical traffic data) of urban road networks can be obtained through vehicle GPS information, loop detectors, roadside cameras, etc. In the long run, traffic demand or traffic flow follows certain patterns. Considering this, this application aims to optimize the signal control of isolated intersections of urban road networks based on long-term historical traffic data, thereby alleviating the current situation of urban traffic congestion.

[0033] Based on the above, this application proposes a traffic signal control method. First, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the traffic light that allows passage, and each isolated intersection corresponds to one traffic signal information. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to perform traffic signal control optimization processing according to the direction with the largest road network green wave bandwidth to obtain a traffic signal coordination control scheme for the road network. Since traffic demand / flow follows certain patterns in the long run, optimizing the traffic signal information for each isolated intersection using long-term historical traffic data and an isolated intersection optimization model yields relatively accurate results. Using this traffic signal information as input, a road network green wave coordination optimization model is employed to coordinate and optimize the traffic lights across the road network. This allows for the determination of a suitable traffic signal coordination control scheme for the current road network. By controlling the permitted traffic lights at N isolated intersections according to this determined scheme, the road network can be guaranteed to have the maximum green wave bandwidth, thereby effectively alleviating traffic congestion.

[0034] The traffic signal control method provided in this application embodiment can be executed by traffic signal control equipment. The traffic signal control equipment may include a terminal or a server. The terminal may include terminal devices such as mobile phones, laptops, vehicle terminals, and smart wearable devices. The server may refer to an independent physical server, a server cluster composed of multiple servers, or a cloud server capable of cloud computing.

[0035] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0036] See Figure 1 This is a flowchart illustrating a traffic signal control method provided in an embodiment of this application. Figure 1 The control method shown can be executed by the traffic signal control equipment, specifically by the processor of the control equipment. Figure 1 The control method shown may include the following steps:

[0037] Step S101: Based on the historical traffic data of N isolated intersections, the isolated intersection optimization model is used to perform isolated optimization processing to obtain N traffic signal information corresponding to the N isolated intersections.

[0038] Historical traffic data for each isolated intersection can include traffic flow data and channelization schemes. Road traffic channelization refers to the use of traffic signs, markings, various island-like structures, different road surface colors, guardrails, medians, barriers, and other facilities and methods to guide, separate, and control pedestrians and traffic flows of different vehicle types, directions, speeds, and motion states. This ensures that traffic flows, like water in a channel, follow a specific direction and route, operating safely and orderly without interference, thus achieving the goal of separating and controlling traffic flow. The main functions of channelization design are to regulate vehicle movement, reduce traffic conflicts, effectively organize traffic flow through intersections in an orderly manner, maximize the utilization of road resources, and effectively ensure the safety of pedestrians and bicycles while minimizing traffic conflicts.

[0039] There is a one-to-one correspondence between N traffic signal information and N isolated intersections. This means that the historical traffic information of an isolated intersection is optimized using an isolated intersection optimization model to obtain the traffic signal information for that intersection. The traffic signal information mainly includes the display duration and signal cycle of the "allow passage" traffic light. The display duration can be simply understood as the reciprocal of the display length; for example, if the display starts at 10 seconds, the display duration is 10. The signal cycle refers to how often the "allow passage" traffic light is displayed. As is well known, traffic lights controlling traffic entities include three types: prohibition traffic lights, waiting traffic lights, and permitting traffic lights. In daily life, red lights are typically used to indicate prohibition traffic lights, yellow lights to indicate waiting traffic lights, and streetlights to indicate permitting traffic lights. In certain special scenarios, it is not excluded that other colors of traffic lights can be used to represent the above-mentioned traffic lights; this application does not specifically limit this.

[0040] In one embodiment, during step S101, the isolated intersection is optimized, and the decision variable is the start time of the traffic light allowing passage, denoted by θ. i，j The duration of traffic lights that indicate and permit passage is indicated by... Indicated by θ. i，j The start time of the traffic light indicating the permitted passage for turning behavior (i, j) on approach lane i. This indicates the duration of the traffic light signal that allows passage for a turning action (i, j) on approach lane i. The turning action (i, j) represents the action from approach lane i to exit lane j. For example, consider a typical four-approach intersection. Figure 2 This is a schematic diagram of a four-entry intersection provided in an embodiment of this application. Figure 2It includes four inbound lanes, namely Link1, Link3, Link5 and Link7, and four outbound lanes, namely Link2, Link4, Link6 and Link8.

[0041] In one embodiment, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. This may include: determining the optimization constraint function and optimization objective of the corresponding isolated intersection based on the historical traffic data of each isolated intersection; and optimizing the corresponding isolated intersection based on the optimization constraint function and optimization objective of each isolated intersection using the isolated intersection signal optimization model to obtain the traffic signal information of each isolated intersection.

[0042] Optionally, for an isolated intersection, determining the corresponding optimization constraint function and optimization objective based on the historical traffic protection of each isolated intersection may include the following steps S11-S15:

[0043] Step S11: For each isolated intersection, set the signal period constraint based on the maximum and minimum signal period values. Assume the maximum signal period is represented by C. max The minimum value of the signal period is denoted as C. min Then the signal period constraint of an isolated intersection can be expressed by the following formula:

[0044]

[0045] In the above formula, ξ is the reciprocal of the signal period, i.e.

[0046] Step S12: Based on the signal cycle of the isolated intersection and the minimum duration of the traffic signal that allows passage, determine the duration constraint of the traffic signal that allows passage, and set the start time constraint of the traffic signal that allows passage at the isolated intersection.

[0047] For each isolated intersection, there is no strict restriction on the start time of the permitted traffic signal. For simplicity, a normalized start time and duration for the permitted traffic signal can be used, and the start time and duration satisfy the following constraints, namely, the start time constraint and duration constraint are shown below:

[0048] 0≤θ i，j ≤1

[0049]

[0050] Where ξ represents the reciprocal of the signal period, g represents the minimum duration of the traffic light that allows passage, and θi，j This indicates the start time of the traffic light signal that allows passage at an isolated intersection. This indicates the duration of the traffic light signal that allows passage at an isolated intersection. It should be noted that "allow passage" here means that (i, j) is allowed to pass, and (i, j) refers to the turning behavior from approach lane i to exit lane j.

[0051] Step S13: Determine the signal conflict constraint of the isolated intersection based on the duration of waiting for the traffic light.

[0052] It should be understood that at an isolated intersection, if two turning actions conflict, both turns cannot simultaneously be signaled as allowing passage. Two conflicting turning actions can be represented as (i, j) and (m, l). If turning action (i, j) precedes (m, l), then the 0-1 variable Ω... i，j，m，l =0; if the turning action (i, j) follows (m, l), then the 0-1 variable Ω i，j，m，l =1. Therefore, the steering signal conflict constraint can be expressed by the following formula:

[0053] Ω i，j，m，l +Ω m，l，i，j =0

[0054]

[0055] In the above formula, ω represents the duration of the waiting traffic light for the conflict phase, and M is an infinite number.

[0056] Step S14: Determine the flow constraints of isolated intersections based on historical traffic data and flow capacity characterization coefficients of isolated intersections.

[0057] Assuming the traffic demand matrix Q for this isolated intersection is determined based on historical traffic data, the duration of the permitted traffic light signal is expressed as follows: The number of lanes corresponding to the steering action (i, j) is represented by n. i，j The flow capacity characterization coefficient of an isolated intersection is denoted by μ. A larger value indicates a larger flow capacity of the isolated intersection, and vice versa. Therefore, step S14 can be implemented by: combining the traffic demand matrix Q and the duration of the permitted traffic lights. The first multiplication result is obtained by multiplying the number of lanes corresponding to the steering behavior (i, j), and then multiplying the first multiplication result by q. i，j means, specifically:

[0058]

[0059] Then, the traffic demand Q corresponding to the turning behavior (i, j) is... i，j The first multiplication result is obtained by multiplying the first multiplication result by the flow carrying capacity coefficient μ. The second multiplication result is then equated with the first multiplication result and used as the flow constraint. Specifically, the flow constraint can be expressed as follows:

[0060] μ*Q i，j =q i，j

[0061] Step S15: Determine the constraints of the signal cycle, the duration of the allowed traffic signal, the start time, the signal conflict constraints, and the flow constraints of each intersection as the optimization constraint function for the corresponding isolated intersection.

[0062] After determining the optimization constraint function for each isolated intersection through steps S11-S15, the optimization objective of the isolated intersection optimization model is further determined. In this embodiment, the optimization objective for each isolated intersection is the same, which is to maximize the traffic capacity. As mentioned above, μ represents the traffic capacity characteristic coefficient of an isolated intersection. This coefficient is proportional to the traffic capacity of the isolated intersection. The more traffic a single isolated intersection carries, the greater its traffic capacity. Therefore, for each isolated intersection, the optimization objective is to maximize μ, which can be expressed as Maxμ.

[0063] Finally, for each isolated intersection, the signal optimization model is solved using the aforementioned determined optimization constraint functions and optimization objectives to obtain the traffic signal information for each isolated intersection. Specifically, since the optimization constraint functions of the isolated intersection signal optimization model are all linear, they can be solved quickly using the gurobi solver.

[0064] Step S102: Based on N traffic signal information, optimize traffic signal control according to the direction with the largest green wave bandwidth in the road network through the road network green wave coordination optimization model, and obtain the traffic signal coordination control method of the road network.

[0065] The road network green wave coordination optimization model can be understood as integrating N isolated intersections together, taking into account the traffic signal information of each isolated intersection, and optimizing traffic signal control to maximize the green wave bandwidth of the road network, thereby ensuring a larger vehicle throughput and solving urban traffic congestion.

[0066] The traffic signal coordination control method is used to indicate the display time and duration of the permitted communication traffic lights at N isolated intersections. After control is implemented according to the traffic signal coordination control method, it can be guaranteed that the green wave bandwidth in the road network is the largest compared to other traffic signal control methods.

[0067] In one embodiment, step S102, based on N traffic signal information, optimizes traffic signal control according to the direction with the largest green wave bandwidth using a road network green wave coordination optimization model, to obtain a road network traffic signal coordination control method, which can be implemented through the following steps S111-S115:

[0068] Step S111: Determine the common cycle based on the N signal cycles from the N traffic signal information.

[0069] As an optional implementation, one can iterate through N traffic signal information cycles and select the longest cycle as the common cycle. This process can be expressed by the following formula:

[0070] C N =Max{C1, C2, ... C n}

[0071] Among them, C N Indicates the common period, C i The signal period in the traffic signal information of isolated intersection i is represented by i, which is an integer greater than or equal to 1 and less than or equal to N.

[0072] Step S112: Based on the duration of the permitted traffic signal for each isolated intersection in the N traffic information, update the duration constraint of the permitted traffic signal and update the display time constraint of the permitted communication traffic signal.

[0073] Optionally, similar to the isolated intersection optimization model, a normalized allowable start time and duration can be used. For each intersection, there is no strict limit to the allowable start time, but for ease of calculation, the duration of the allowable traffic signal is set between 0 and 1. For example, for isolated intersection n, the updated allowable traffic signal duration θ for turning behavior (i, j) n，i，j It can be represented as:

[0074] 0≤θ n，i，j ≤1

[0075] From a road network perspective, to meet traffic demand, the duration of the permitted traffic signal for turning behavior at each isolated intersection needs to be determined from the traffic signal information of each isolated intersection as a constraint. Therefore, for turning behavior (i, j) at an isolated intersection n, the duration constraint of the permitted traffic signal is updated based on the duration of the permitted traffic signal at each isolated intersection, which can be expressed by the following formula:

[0076]

[0077] in, The duration of the permitted traffic light signal for the turning behavior (i, j) at the updated isolated intersection n. This represents the duration of the traffic light signal that allows passage for the turning behavior (i, j) of isolated intersection n obtained through the isolated intersection optimization model.

[0078] Step S113: Obtain the signal conflict constraints for each isolated intersection. Optionally, the specific implementation of this step can be found in the description of step S13 above, and will not be repeated here.

[0079] Step S114: Determine the optimization objective of the road network green wave coordination optimization model.

[0080] While ensuring the safe operation of traffic lights at isolated intersections, the optimization objective of the road network green wave coordination optimization model is to maximize the green wave bandwidth of all road segments in the road network.

[0081] Optionally, determining the optimization objective of the road network green wave coordination optimization model may include: calculating the bandwidth of each road segment in the road network, where the bandwidth includes the green wave bandwidth; summing the bandwidths of each road segment in the road network, and maximizing the green wave bandwidth in the summation result as the optimization objective. For example, the optimization objective of the road network green wave coordination optimization model can be expressed as the following formula:

[0082]

[0083] in, This represents the bandwidth of a single road segment, and n represents the number of road segments.

[0084] Calculating the bandwidth of each road segment can include the following steps:

[0085] (1) Obtain the traffic flow of a road segment; here, a road segment refers to any one of the n road segments in the road network, see [link to relevant documentation]. Figure 3 This is a road network diagram provided in an embodiment of this application. Figure 3 In this example, 'n' represents a road segment. Unless otherwise specified, this example uses a single road segment in a road network to illustrate how to calculate the bandwidth of the entire network. The same method can be used to calculate the bandwidth of other road segments in the network, and will not be elaborated upon in this embodiment. The traffic of road segment 'n' can be expressed as 'q'. n This traffic flow can be obtained based on historical traffic data for that road segment.

[0086] (2) Obtain the set of driving behaviors for a road segment. For a road segment n, both its upstream and downstream traffic flows have three directions: left, straight, and right. Without considering right-turn traffic, the set of driving behaviors for a road segment can include four types of driving behaviors: upstream straight-downstream straight-downstream (straight-straight), upstream straight-downstream left-turn (straight-left), upstream left-turn-downstream straight-downstream (left-straight), and upstream left-turn-downstream left-turn (left-left). For example, in... Figure 3 In the above, for road segment n, at isolated intersection i, the driving behaviors related to road segment n include going straight and turning left. At isolated intersection j, the driving behaviors related to road segment n can include going straight and turning left. Therefore, the driving behaviors that may exist on road segment n include turning left from i to road segment n and then going straight, moving left or right from i to road segment n and then turning left, going straight from i to road segment n and then going straight, and going straight from i to road segment n and then turning left.

[0087] (3) For each driving behavior, obtain the green wave bandwidth of the driving behavior, the upstream steering ratio of the upstream driving behavior, and the downstream steering ratio of the downstream driving behavior.

[0088] The upstream driving behavior can include the aforementioned upstream straight-through behavior and upstream left-turn behavior, and the downstream driving behavior includes the aforementioned downstream straight-through behavior and downstream left-turn behavior. The following uses the upstream left-turn behavior-downstream left-turn behavior as an example to introduce how to calculate the bandwidth of the driving behavior. For other driving behaviors, the bandwidth can be calculated in the same way as (3) and (4), and will not be elaborated on in this application embodiment.

[0089] The green wave bandwidth of driving behavior can be used Here, f can represent an upstream left turn, and g can represent a downstream left turn, corresponding to left-to-left driving behavior in the set of driving behaviors. See also Figure 4 This is a schematic diagram of green wave bandwidth calculation provided in the application embodiment. Combined with... Figure 4 The method for calculating green wave bandwidth for this type of driving behavior can include:

[0090] S1. The first start time of obtaining the permitted traffic signal for the upstream left-turn behavior is denoted as θf, and the first duration is denoted as... The second start time of the permitted traffic signal for downstream left-turn behavior is denoted as θ. g The second duration is expressed as

[0091] S2. Add the first start time, the first duration, and the phase difference to obtain the first addition result; add the second start time and the second duration to obtain the second addition result; add the first start time and the phase difference to obtain the third addition result.

[0092] Among them, can be used This represents the result of the first addition operation, where δ represents the phase difference, which can be calculated using the ratio of the length of road segment n to the free-flow velocity. θ represents the result of the second addition operation. f +δ represents the result of the third addition operation.

[0093] S3. Take the minimum value between the first addition result and the second addition result, and take the maximum value between the third operation result and the second start time.

[0094] S4. Subtract the minimum value from the maximum value, and use the result of the subtraction as the green wave bandwidth of the upstream left turn behavior minus the downstream left turn behavior.

[0095] S3 and S4 can be represented by the following formula:

[0096]

[0097] (4) Multiply the green wave bandwidth, flow rate, upstream steering ratio and downstream steering ratio to obtain the bandwidth for each driving behavior.

[0098] For specific driving behaviors, after obtaining the green wave bandwidth, the green wave bandwidth, flow rate, upstream steering ratio, and downstream steering ratio are multiplied to obtain the bandwidth for that driving behavior. Taking left-to-left driving behavior as an example, the bandwidth calculation formula can be expressed as follows:

[0099] (5) The bandwidth of the road segment is obtained by summing the bandwidths of various driving behaviors. Taking road segment n as an example, the bandwidth of each driving behavior on road segment n is calculated by (1)-(4) above, and then these bandwidths are summed to obtain the bandwidth of road segment n. The bandwidth of road segment n can be expressed as:

[0100]

[0101] Step S115: Based on the common period, the duration constraint of the permitted traffic signal, the display time constraint, the signal conflict constraint, and the optimization objective of the road network green wave coordination optimization model, optimize the traffic signal control process according to the direction with the maximum green wave bandwidth of the road network to obtain the traffic signal coordination control scheme of the road network.

[0102] After determining the optimization objective and various constraint functions of the road network green wave coordination optimization model through steps S111-S114, the optimization solution is performed according to the direction that maximizes the green wave bandwidth of the road network, ultimately yielding the traffic signal coordination control scheme. In specific implementation, the Gurobi solver can be used to solve the road network green wave coordination optimization model.

[0103] This application proposes a traffic signal control method. First, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the traffic light that allows passage, and each isolated intersection corresponds to one traffic signal information. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to perform traffic signal control optimization processing according to the direction with the largest road network green wave bandwidth to obtain a road network traffic signal coordination control scheme. Since traffic demand / flow follows certain patterns in the long run, optimizing the traffic signal information for each isolated intersection using long-term historical traffic data and an isolated intersection optimization model yields relatively accurate results. Using this traffic signal information as input, a road network green wave coordination optimization model is employed to coordinate and optimize the traffic lights across the road network. This allows for the determination of a suitable traffic signal coordination control scheme for the current road network. By controlling the permitted traffic lights at N isolated intersections according to this determined scheme, the road network can be guaranteed to have the maximum green wave bandwidth, thereby effectively alleviating traffic congestion.

[0104] pass Figure 1 The embodiment description provides a schematic diagram of another traffic signal control method, see below. Figure 5 As shown. Figure 5 The traffic signal control method can be as follows: First, the channelization prevention and traffic flow data of each intersection (i.e., the aforementioned isolated intersections) are used as inputs to the isolated intersection optimization model to obtain the signal timing of each intersection, mainly referring to the green light duration and start time, as well as the channelization scheme of each intersection. Next, based on the signal timing of each intersection output by the isolated intersection optimization model, the signal cycle and green light duration of each intersection are extracted. A common cycle is determined based on the signal cycle of each intersection, and a constraint function is determined based on the street light duration of each intersection. Based on the common cycle, constraint function, and channelization method of each intersection, a road network green wave coordination optimization model is used for optimization. Finally, a road network coordinated signal control scheme, i.e., a road network traffic signal coordination control scheme, is output.

[0105] Based on the above embodiments of traffic signal control methods, this application provides a traffic signal control device. (See also...) Figure 6 This is a schematic diagram of a traffic signal control device provided in an embodiment of this application. Figure 6 The control device shown can operate the following units:

[0106] The optimization unit 601 is used to perform isolated optimization processing based on the historical traffic data of N isolated intersections through the isolated intersection optimization model to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the permitted communication traffic signal, etc.; one isolated intersection corresponds to one traffic signal information.

[0107] The processing unit 602 is used to perform traffic signal control optimization processing based on the N traffic signal information, according to the direction with the largest green wave bandwidth of the road network, through the road network green wave coordination optimization model, to obtain the traffic signal coordination control scheme of the road network.

[0108] In one embodiment, when the optimization unit 601 performs isolated optimization processing based on historical traffic data of N isolated intersections using the isolated intersection optimization model to obtain N traffic signal information corresponding to the N isolated intersections, it performs the following steps:

[0109] The optimization constraint function and optimization objective for each isolated intersection are determined based on historical traffic data.

[0110] The isolated intersection signal optimization model optimizes the corresponding isolated intersections based on the optimization constraint function and optimization objective of each isolated intersection, thereby obtaining the traffic signal information of each isolated intersection.

[0111] In one embodiment, when the optimization unit 601 determines the optimization constraint function for each isolated intersection based on historical traffic data, it performs the following steps:

[0112] For each isolated intersection, a constraint on the signal period of the isolated intersection is set based on the maximum and minimum values ​​of the signal period;

[0113] Based on the signal cycle of the isolated intersection and the minimum duration of the traffic signal that allows passage, the duration constraint of the traffic signal that allows passage is determined, and the start time constraint of the traffic signal that allows passage at the isolated intersection is set.

[0114] The signal conflict constraints of the isolated intersection are determined based on the duration of waiting for the traffic light.

[0115] The flow constraints of the isolated intersection are determined based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection.

[0116] The constraints of the signal cycle, the duration of the allowed traffic signal, the start time, the signal conflict constraints, and the flow constraints for each intersection are determined as the optimization constraint functions for the corresponding isolated intersection.

[0117] In one embodiment, when the optimization unit 601 determines the flow constraint of the isolated intersection based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection, it performs the following steps:

[0118] Based on the historical traffic data of the isolated intersection, the traffic demand matrix of the isolated intersection is determined, and the traffic demand matrix, the duration of the traffic light that allows passage, and the number of lanes corresponding to the turning behavior (i,j) are multiplied to obtain the first multiplication result; i and j represent the two roads of the isolated intersection.

[0119] The traffic demand and flow capacity characterization coefficient corresponding to the turning behavior (i,j) are multiplied to obtain the second multiplication result; the flow capacity characterization system is used to positively characterize the flow that the isolated intersection can carry;

[0120] The result of the first multiplication operation is equal to the result of the second multiplication operation, and this is used as the flow constraint.

[0121] In one embodiment, when the processing unit 602 performs traffic signal control optimization processing based on the N traffic signal information and according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model to obtain the traffic signal coordination control scheme of the road network, it executes the following steps:

[0122] The common cycle is determined based on the N signal cycles from the N traffic signal information;

[0123] Based on the duration of the permitted traffic signal for each isolated intersection in the N traffic information, update the duration constraint of the permitted traffic signal and update the display time constraint of the permitted communication traffic signal.

[0124] Obtain the signal conflict constraints for each isolated intersection;

[0125] Determine the optimization objective of the road network green wave coordination optimization model;

[0126] Based on the common period, the duration constraint of the updated permitted traffic signal, the display time constraint, the signal conflict constraint, and the optimization objective of the road network green wave coordination optimization model, the traffic signal control optimization process is performed in the direction of maximizing the road network green wave bandwidth to obtain the road network traffic signal coordination control scheme.

[0127] In one embodiment, when determining the optimization objective of the road network green wave coordination optimization model, the processing unit 602 performs the following steps:

[0128] For each road segment in the road network, the bandwidth of the road segment is calculated, including the green wave bandwidth;

[0129] The bandwidths of each road segment in the road network are summed, and the green wave bandwidth in the summation result is maximized as the optimization objective.

[0130] In one embodiment, when calculating the bandwidth of a road segment, the processing unit 602 performs the following steps:

[0131] Obtain the traffic flow of the road segment; obtain the set of driving behaviors for the road segment, the set of driving behaviors including upstream straight-downward driving behavior, upstream straight-downward left-turning behavior, upstream left-turning behavior - downstream straight-downward driving behavior, and upstream left-turning behavior - downstream left-turning behavior;

[0132] For each driving behavior, the green wave bandwidth of the driving behavior, the upstream steering ratio corresponding to the upstream driving behavior, and the downstream steering ratio corresponding to the downstream driving behavior are obtained;

[0133] The bandwidth for each driving behavior is obtained by multiplying the green wave bandwidth, the flow rate, the upstream steering ratio, and the downstream steering ratio.

[0134] The bandwidth of the road segment is obtained by summing the bandwidths of various driving behaviors.

[0135] In one embodiment, for a driving behavior of upstream left turn behavior - downstream left turn behavior, the processing unit 602 performs the following steps when the green wave bandwidth of the behavior is:

[0136] The system acquires the first start time and first duration of the permitted traffic signal for the upstream left-turn behavior, and the second start time and second duration of the permitted traffic signal for the downstream left-turn behavior.

[0137] The first start time, the first duration, and the phase difference are added together to obtain a first addition result; the second start time and the second duration are added together to obtain a second addition result; the first start time and the phase difference are added together to obtain a third addition result.

[0138] The minimum value is taken from the first summation result and the second summation result, and the maximum value is taken from the third summation result and the second start time;

[0139] The minimum value and the maximum value are subtracted, and the result of the subtraction is used as the green wave bandwidth of the upstream left turn behavior minus the downstream left turn behavior.

[0140] In this embodiment, firstly, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections, resulting in N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the permitted traffic light, with one traffic signal information corresponding to one isolated intersection. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to optimize traffic signal control according to the direction with the maximum green wave bandwidth, resulting in a traffic signal coordination control scheme for the road network. Since traffic demand / flow follows certain patterns in the long term, optimizing the traffic signal information of each isolated intersection based on long-term historical traffic data and the isolated intersection optimization model is relatively accurate. Using the traffic signal information of each isolated intersection as input, the road network green wave coordination optimization model is used to coordinate and optimize the road network traffic lights, determining a suitable traffic signal coordination control scheme for the current road network. Controlling the permitted traffic lights of the N isolated intersections according to the determined traffic signal coordination control scheme ensures that the road network has the maximum green wave bandwidth, thereby effectively alleviating traffic congestion.

[0141] Based on the above-described traffic signal control method and control device embodiments, this application also provides a traffic signal control device, see [link to relevant documentation]. Figure 7 This is a schematic diagram of the structure of a traffic signal control device provided in an embodiment of this application. Figure 7 The control device shown may include a processor 701, an input interface 702, an output interface 703, and a computer storage medium 703. The processor 701, input interface 702, output interface 703, and computer storage medium 703 may be connected via a bus or other means.

[0142] Computer storage medium 704 can be stored in the memory of the control device. The computer storage medium 704 is used to store computer programs, and the processor 701 is used to execute the computer programs stored in the computer storage medium 704. The processor 701 (or CPU (Central Processing Unit)) is the computing and control core of the control device, and is suitable for implementing one or more computer programs, specifically for loading and executing them.

[0143] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the traffic light that allows passage; one isolated intersection corresponds to one traffic signal information.

[0144] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0145] In this embodiment, firstly, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections, resulting in N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the permitted traffic light, with one traffic signal information corresponding to one isolated intersection. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to optimize traffic signal control according to the direction with the maximum green wave bandwidth, resulting in a traffic signal coordination control scheme for the road network. Since traffic demand / flow follows certain patterns in the long term, optimizing the traffic signal information of each isolated intersection based on long-term historical traffic data and the isolated intersection optimization model is relatively accurate. Using the traffic signal information of each isolated intersection as input, the road network green wave coordination optimization model is used to coordinate and optimize the road network traffic lights, determining a suitable traffic signal coordination control scheme for the current road network. Controlling the permitted traffic lights of the N isolated intersections according to the determined traffic signal coordination control scheme ensures that the road network has the maximum green wave bandwidth, thereby effectively alleviating traffic congestion.

[0146] This application embodiment also provides a computer storage medium (memory), which is a memory device of a control device used to store programs and data. It is understood that the computer storage medium here may include the built-in storage medium of the control device, or it may include an extended storage medium supported by a data processing device. The computer storage medium provides storage space that stores the operating system of the control device. Furthermore, one or more computer programs suitable for loading and execution by the processor 701 are also stored in this storage space. It should be noted that the computer storage medium here may be a high-speed RAM memory, or a non-volatile memory, such as at least one disk storage device; optionally, it may also be at least one computer storage medium located remotely from the aforementioned processor.

[0147] In one embodiment, one or more computer programs stored in the computer storage medium can be loaded and executed by the processor 701:

[0148] An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the traffic light that allows passage; one isolated intersection corresponds to one traffic signal information.

[0149] Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network.

[0150] In one embodiment, when the processor 701 performs isolated optimization processing based on historical traffic data of N isolated intersections using an isolated intersection optimization model to obtain N traffic signal information corresponding to the N isolated intersections, it executes the following steps:

[0151] Based on the historical traffic data of each isolated intersection, the optimization constraint function and optimization objective of the corresponding isolated intersection are determined; the isolated intersection signal optimization model is used to optimize and solve the corresponding isolated intersection based on the optimization constraint function and optimization objective of each isolated intersection, so as to obtain the traffic signal information of each isolated intersection.

[0152] In one embodiment, when the processor 701 determines the optimization constraint function for each isolated intersection based on historical traffic data, it performs the following steps:

[0153] For each isolated intersection, a constraint on the signal period of the isolated intersection is set based on the maximum and minimum values ​​of the signal period;

[0154] Based on the signal cycle of the isolated intersection and the minimum duration of the traffic signal that allows passage, the duration constraint of the traffic signal that allows passage is determined, and the start time constraint of the traffic signal that allows passage at the isolated intersection is set.

[0155] The signal conflict constraints of the isolated intersection are determined based on the duration of waiting for the traffic light.

[0156] The flow constraints of the isolated intersection are determined based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection.

[0157] The constraints of the signal cycle, the duration of the allowed traffic signal, the start time, the signal conflict constraints, and the flow constraints for each intersection are determined as the optimization constraint functions for the corresponding isolated intersection.

[0158] In one embodiment, when the processor 701 determines the flow constraint of the isolated intersection based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection, it performs the following steps:

[0159] Based on the historical traffic data of the isolated intersection, the traffic demand matrix of the isolated intersection is determined, and the traffic demand matrix, the duration of the traffic light that allows passage, and the number of lanes corresponding to the turning behavior (i,j) are multiplied to obtain the first multiplication result; i and j represent the two roads of the isolated intersection.

[0160] The traffic demand and flow capacity characterization coefficient corresponding to the turning behavior (i,j) are multiplied to obtain the second multiplication result; the flow capacity characterization system is used to positively characterize the flow that the isolated intersection can carry;

[0161] The result of the first multiplication operation is equal to the result of the second multiplication operation, and this is used as the flow constraint.

[0162] In one embodiment, when the processor 701 performs traffic signal control optimization processing based on the N traffic signal information and according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model to obtain the traffic signal coordination control scheme of the road network, it executes the following steps:

[0163] The common cycle is determined based on the N signal cycles from the N traffic signal information;

[0164] Based on the duration of the permitted traffic signal for each isolated intersection in the N traffic information, update the duration constraint of the permitted traffic signal and update the display time constraint of the permitted communication traffic signal.

[0165] Obtain the signal conflict constraints for each isolated intersection;

[0166] Determine the optimization objective of the road network green wave coordination optimization model;

[0167] Based on the common period, the duration constraint of the updated permitted traffic signal, the display time constraint, the signal conflict constraint, and the optimization objective of the road network green wave coordination optimization model, the traffic signal control optimization process is performed in the direction of maximizing the road network green wave bandwidth to obtain the road network traffic signal coordination control scheme.

[0168] In one embodiment, when determining the optimization objective of the road network green wave coordination optimization model, the processor 701 performs the following steps:

[0169] For each road segment in the road network, the bandwidth of the road segment is calculated, including the green wave bandwidth;

[0170] The bandwidths of each road segment in the road network are summed, and the green wave bandwidth in the summation result is maximized as the optimization objective.

[0171] In one embodiment, when calculating the bandwidth of a road segment, the processor 701 performs the following steps:

[0172] Obtain the traffic flow of the aforementioned road segment;

[0173] Obtain the set of driving behaviors for the road segment, which includes upstream straight-downward driving behavior, upstream straight-downward left-turning behavior, upstream left-turning behavior, downstream straight-downward driving behavior, and upstream left-turning behavior, downstream left-turning behavior.

[0174] For each driving behavior, the green wave bandwidth of the driving behavior, the upstream steering ratio corresponding to the upstream driving behavior, and the downstream steering ratio corresponding to the downstream driving behavior are obtained;

[0175] The bandwidth for each driving behavior is obtained by multiplying the green wave bandwidth, the flow rate, the upstream steering ratio, and the downstream steering ratio.

[0176] The bandwidth of the road segment is obtained by summing the bandwidths of various driving behaviors.

[0177] In one embodiment, for a driving behavior of upstream left turn behavior - downstream left turn behavior, when the processor 701 obtains the green wave bandwidth of the driving behavior, it performs the following steps:

[0178] The first start time and first duration of the permitted traffic signal for the upstream left-turn behavior are obtained, as well as the second start time and second duration of the permitted traffic signal for the downstream left-turn behavior.

[0179] The first start time, the first duration, and the phase difference are added together to obtain a first addition result; the second start time and the second duration are added together to obtain a second addition result; the first start time and the phase difference are added together to obtain a third addition result.

[0180] The minimum value is taken from the first summation result and the second summation result, and the maximum value is taken from the third summation result and the second start time;

[0181] The minimum value and the maximum value are subtracted, and the result of the subtraction is used as the green wave bandwidth of the left-turn-left-turn driving behavior.

[0182] In this embodiment, firstly, an isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections, resulting in N traffic signal information corresponding to the N isolated intersections. Each traffic signal information includes the display duration and signal cycle of the permitted traffic light, with one traffic signal information corresponding to one isolated intersection. Then, based on the N traffic signal information, a road network green wave coordination optimization model is used to optimize traffic signal control according to the direction with the maximum green wave bandwidth, resulting in a traffic signal coordination control scheme for the road network. Since traffic demand / flow follows certain patterns in the long term, optimizing the traffic signal information of each isolated intersection based on long-term historical traffic data and the isolated intersection optimization model is relatively accurate. Using the traffic signal information of each isolated intersection as input, the road network green wave coordination optimization model is used to coordinate and optimize the road network traffic lights, determining a suitable traffic signal coordination control scheme for the current road network. Controlling the permitted traffic lights of the N isolated intersections according to the determined traffic signal coordination control scheme ensures that the road network has the maximum green wave bandwidth, thereby effectively alleviating traffic congestion.

Claims

1. A method for controlling traffic signals, characterized in that, include: An isolated intersection optimization model is used to perform isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the traffic light that allows passage; one isolated intersection corresponds to one traffic signal information. Based on the N traffic signal information, the traffic signal control optimization process is carried out according to the direction with the largest green wave bandwidth of the road network through the road network green wave coordination optimization model, so as to obtain the traffic signal coordination control scheme of the road network. The step of optimizing traffic signal control based on the N traffic signal information by using a road network green wave coordination optimization model in the direction with the largest road network green wave bandwidth to obtain a road network traffic signal coordination control scheme includes: A common period is determined based on N signal periods from the N traffic signal information; the duration constraint of the allowed traffic signal and the display time constraint of the allowed traffic signal are updated based on the duration of the allowed traffic signal at each isolated intersection from the N traffic signal information; signal conflict constraints at each isolated intersection are obtained; the optimization objective of the road network green wave coordination optimization model is determined; based on the common period, the updated duration constraint of the allowed traffic signal, the display time constraint, the signal conflict constraint, and the optimization objective of the road network green wave coordination optimization model, traffic signal control optimization processing is performed in the direction with the largest road network green wave bandwidth to obtain the road network traffic signal coordination control scheme; The optimization objective of the road network green wave coordination optimization model is determined as follows: for each road segment in the road network, the bandwidth of the road segment is calculated, and the bandwidth includes the green wave bandwidth; the bandwidths of each road segment in the road network are added together, and the maximum green wave bandwidth in the addition result is taken as the optimization objective; The calculation of the bandwidth of the road segment includes: obtaining the traffic flow of the road segment; obtaining a set of driving behaviors for the road segment, the set of driving behaviors including upstream straight-downward driving behavior, upstream straight-downward left-turning behavior, upstream left-turning behavior, downstream straight-downward driving behavior, and upstream left-turning behavior; for each driving behavior, obtaining the green wave bandwidth of the driving behavior, the upstream steering ratio corresponding to the upstream driving behavior, and the downstream steering ratio corresponding to the downstream driving behavior; multiplying the green wave bandwidth, the traffic flow, the upstream steering ratio, and the downstream steering ratio to obtain the bandwidth of each driving behavior; and adding the bandwidths of various driving behaviors to obtain the bandwidth of the road segment. For the driving behavior of upstream left turn behavior and downstream left turn behavior, the green wave bandwidth of the driving behavior is obtained, including: The system acquires the first start time and first duration of the permitted traffic signal for the upstream left-turn behavior, and the second start time and second duration of the permitted traffic signal for the downstream left-turn behavior; it adds the first start time, the first duration, and the phase difference to obtain a first summation result, and adds the second start time and the second duration to obtain a second summation result; it adds the first start time and the phase difference to obtain a third summation result; it takes the minimum value between the first summation result and the second summation result, and the maximum value between the third summation result and the second start time; it subtracts the minimum value from the maximum value, and uses the subtraction result as the green wave bandwidth of the upstream left-turn behavior minus the downstream left-turn behavior.

2. The method according to claim 1, wherein the isolated intersection optimization model performs isolated optimization processing based on historical traffic data of N isolated intersections to obtain N traffic signal information corresponding to the N isolated intersections, comprising: The optimization constraint function and optimization objective for each isolated intersection are determined based on historical traffic data. The isolated intersection optimization model is used to optimize and solve the corresponding isolated intersections based on the optimization constraint function and optimization objective of each isolated intersection, thereby obtaining the traffic signal information of each isolated intersection.

3. The method according to claim 2, characterized in that, The process of determining the optimization constraint function for each isolated intersection based on historical traffic data includes: For each isolated intersection, a constraint on the signal period of the isolated intersection is set based on the maximum and minimum values ​​of the signal period; Based on the signal cycle of the isolated intersection and the minimum duration of the traffic signal that allows passage, the duration constraint of the traffic signal that allows passage is determined, and the start time constraint of the traffic signal that allows passage at the isolated intersection is set. The signal conflict constraints of the isolated intersection are determined based on the duration of waiting for the traffic light. The flow constraints of the isolated intersection are determined based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection. The constraints of the signal cycle, the duration of the allowed traffic signal, the start time, the signal conflict constraints, and the flow constraints for each intersection are determined as the optimization constraint functions for the corresponding isolated intersection.

4. The method according to claim 3, characterized in that, The step of determining the flow constraint of the isolated intersection based on the historical traffic data of the isolated intersection and the flow capacity characterization coefficient of the isolated intersection includes: Based on the historical traffic data of the isolated intersection, the traffic demand matrix of the isolated intersection is determined, and the traffic demand matrix, the duration of the traffic light that allows passage, and the number of lanes corresponding to the turning behavior (i,j) are multiplied to obtain the first multiplication result; i and j represent the two roads of the isolated intersection. The traffic demand and flow capacity characterization coefficient corresponding to the turning behavior (i,j) are multiplied to obtain the second multiplication result; the flow capacity characterization coefficient is used to positively characterize the flow that the isolated intersection can carry; The result of the first multiplication operation is equal to the result of the second multiplication operation, and this is used as the flow constraint.

5. A traffic signal control device for performing the method according to any one of claims 1-4, characterized in that, include: The optimization unit is used to perform isolated optimization processing based on the historical traffic data of N isolated intersections through the isolated intersection optimization model, and obtain N traffic signal information corresponding to the N isolated intersections. The traffic signal information includes the display duration and signal cycle of the traffic light that allows passage; one isolated intersection corresponds to one traffic signal information. The processing unit is used to optimize traffic signal control based on the N traffic signal information by using the road network green wave coordination optimization model in the direction with the largest road network green wave bandwidth, so as to obtain the traffic signal coordination control scheme of the road network.

6. A traffic signal control device, characterized in that, include: A processor is used to implement one or more computer programs; A computer storage medium storing one or more computer programs adapted for loading by a processor and executing the traffic signal control method as described in any one of claims 1-4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the traffic signal control method as described in any one of claims 1-4.

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